Too many face identifiers

Why am I seeing more face identifiers than the number of people in the video?

State-of-the-art face detection and identification algorithms still occasionally make errors. For instance, our algorithm sometimes detects faces in shadows or reflections. Other times, our algorithm falsely attributes a new identity to someone who has already been in the video, sometimes due to changes in lighting or occlusion. These errors can result in additional face IDs. We are still working to fine-tune our algorithm to minimize errors in the contexts that our customers care about.